Electrical connectors

ABSTRACT

An electrical connector for interconnecting circuit boards has an insulating body with adjacently disposed recesses defined along at least one of its sides and open at the sides. A connector element is disposed in each of the recesses having a contact foot extending outwardly from the recess for mounting to one circuit board and a movable contact head extending above an uppermost face of the insulating body for being resiliently pressed into contact with another circuit board. The connector element includes a flexible stem portion between the contact head and a horizontal portion mounted to the insulating body such that the flexible stem portion bends back over the mounted portion only once.

FIELD OF INVENTION

The present invention relates to electrical connectors and moreparticularly to electrical connectors used to interconnect electronicassemblies such as, for example, printed circuit boards, which arerequired to he mounted one adjacent another, often, but not necessarily,in a vertically-arranged stack. Such electronic assemblies will bereferred to herein as "boards".

BACKGROUND TO THE INVENTION

Apart from hard wiring the boards one to another, prior art methods ofinterconnecting the boards include the use of edge connectors carried bythe boards which engage with complementary fixed connectors carriedwithin a frame mounting the boards, interconnection being requiredbetween the complementary fixed connectors to provide the necessaryconnections from one board to another.

Such systems are inconvenient and costly, requiring numerous individualcomponent parts, and the assembly of those parts into an interconnectionsystem. In addition, removal or replacement of individual boards of anassembly is likely to difficult and thus introduce further cost inservice and maintenance.

It is an object of the present invention to provide an improved means ofinterconnecting boards as herein defined.

SUMMARY OF THE INVENTION

According to the present invention electrical connection means forinterconnecting two physically adjacent boards, as herein defined,comprises an electrically insulating body which mounts one or moreelectrically conducting elements, each such conducting element having afirst portion adapted to electrically contact an electrically conductingpart of one board, and a second portion adapted to contact anelectrically conducting part of an adjacent board, to provide electricalconnection therebetween.

One of said portions may be adapted to be physically attached to theelectrically conducting part of its respective board, and the other ofsaid portions to form a pressure contact with the electricallyconducting part of the other board.

Alternatively the body of the connector may be physically attached to,or located upon, one or other of the two boards and pressure contactmade by both portions of the connector element to the respectiveconducting parts of the two boards.

In one form of connector in accordance with the invention, theinsulating body of the connector may lie between the boards to beinterconnected, and connection may be made between contacts carriedrespectively by the opposed faces of the two boards.

In a further form, the boards to be interconnected may lie one upon theother, and connection may be made between contacts carried respectivelyupon the upper faces of the two boards.

Employing a series of connectors in accordance with the invention, aseries of boards may be interconnected in stack without the need for anexternal mechanical framework or associated interconnections.

It will be apparent that connectors in accordance with the inventionprovide a more ready and less expensive means of interconnectingadjacent boards one to another, and of creating an interconnected stackof a series of such boards.

BRIEF DESCRIPTION OF DRAWINGS

In order that features and advantages of the present invention may befurther appreciated, two embodiments thereof will be described, by wayof example, with reference to the accompanying drawings of which:

FIGS. 1, 2 and 3 show respectively views from the top, side and below ofan electrical connector in accordance with the invention:

FIG. 4 is a transverse section through the connector of FIGS. 1, 2 and3, taken along the line A--A, looking in the direction of the arrows;

FIG. 5 is a transverse section of another form of connector inaccordance with the invention;

FIGS. 6 & 7 are views or the connector of FIG. 5 from one side and belowrespectively, on a different scale; and

FIG. 8 is a further transverse view of the connector of FIG. 5 assembledwith, and interconnecting two boards.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIGS. 1 to 4, the first electrical connector comprises abody 10 of electrically insulating material in the form of a plasticsmoulding, whose opposed longitudinal faces 12 and 14 are each providedwith a series of opposed recesses, such as 16 and 18 respectively (seeFIG. 4), in which identical contact elements such as 20 and 22 aremounted.

The body 10 may typically be moulded of STANYL (TM) high temperatureresistant nylon 46, and the contact elements 20 formed ofberyllium-copper strip material 0.1 mm thick.

Each contact element is shaped to provide a head 24 in the form of aninverted letter V at the upper extremity of the contact element and aflat foot 26 at the lower extremity.

Head 24, which is intended to make pressure contact with a contact padupon one printed circuit board is gold plated to optimise electricalcontact between contact element 20 and the respective contact paid,carried upon the board to be mounted adjacent the upper face 32 of body10.

Foot 26, which is intended to be surface mounted by soldering to acontact pad upon the other printed circuit board, is tinned with atin-lead alloy to permit ready attachment thereto.

Each contact element 20 is shaped and mounted to permit head 24 to flexoutwardly and downwardly upon stem 34, about turnover 36, when assembledwith an upper printed circuit board, the lower face of which will lie incontact with the upper face 32 of moulding 10, when the upper board ispressed into contact with the connector.

Referring now to the further connector shown in FIGS. 5 to 8 of thedrawings, a series of contact elements 50, are mounted within recesses52 arranged in two opposed rows 54 and 56, one on each side of a bodymoulding 58 of electrically insulating material.

Each contact element 50 comprises a generally V-shaped portion, one limb60 of which lies in contact with the upper face of the recess 52, andthe other 62 partly projects through the inerture slot 64 in the lowerface of recess 52.

The end-portion of limb 60 is continued and stepped to provide a foot66, intended to be surface mounted upon a complementary contact carriedby one of the two boards to be interconnected, and the end portion 68 oflimb 62 is bent upwardly toward the recess 52. to provide a sprungcontact face 69 to engage a complementary contact carried by the otherof the two boards to be interconnected.

FIG. 8 shows the same connector assemnbled with a pair of boards 70 and72, with appropriately positioned contact pads 74 and 76 respectively,on the upper surface of each, to permit interconnection by means of thecontact elements 50.

The end portion 68 of each contact element 50 projects through aperture64, and allows contact faces to contact pads 76 upon the upper face ofboard 72, the lower part of connector body 58 projecting through anappropriately dimensioned aperture in the upper board 70, tomechanically contact the upper face of lower board 72.

It will he appreciated that the connector described in relation to FIGS.5 to 8 of the drawings will normally be carried upon the upper board 70by virtue of the contact feet 66 being surface mounted by solderattachment to contact pads 74, and, upon assembly of the two boards 70and 72, contact faces 69 will engage pads 76 upon the lower board 72.The complete assembly may be held together by appropriately mountingboard 70 to board 72, for example by interengaging pegs and apertures,or otherwise.

I claim:
 1. An electrical connector for interconnecting at least a firstcircuit board to a second circuit board, comprising:an insulating bodyhaving an upper portion defining an uppermost first face configured fordisposition adjacent a face of a first circuit board, a lower portiondefining a bottommost face, and longitudinal sides, said insulating bodyfurther defining adjacently disposed recesses defined in at least one ofsaid sides, said recesses being at said side and defined between innersurfaces of said upper and lower portions; a connector element disposedin each of said recesses, each said connector element having a first endand a second end, and further comprising: a contact foot definedgenerally at said second end extending outwardly from said recess anddisposed for contact mounting to a second circuit board; a generallyhorizontal mounted portion intermediate said first and second endsdisposed within said recess and mounted directly against an innersurface of said recess lower portion. a resiliently movable contact headdefined generally at said first end and disposed above a plane of saiduppermost first face, said contact head movable towards said uppermostfirst face upon being pressed into mating contact with the first circuitboard; and a flexible stem portion extending between said horizontalmounted portion and said contact head, said flexible stem portion bentback over said horizontal mounted portion only once between saidhorizontal mounted portion and said contact head.
 2. The connector as inclaim 1, wherein said flexible stem portion comprises a single turnoversection directly adjacent said horizontal mounted portion where saidflexible stem portion bends back over said horizontal mounted portion.3. The connector as in claim 2, wherein said flexible stem portion isessentially straight between said turnover section and said contacthead.
 4. The connector as in claim 3, wherein flexible stem portionextends at an angle of generally less than ninety degrees relative tosaid horizontal mounted portion.
 5. The connector as in claim 1, whereinsaid flexible stem portion is bent back over said horizontal mountedportion at a single turnover section that is disposed within said recesssuch that said flexible stem portion and said horizontal mounted portiondefine an outwardly facing open-ended configuration.
 6. The connector asin claim 5, wherein said flexible stem portion and said horizontalmounted portion define a generally V-shaped open-ended configuration. 7.The connector as in claim 5, wherein said flexible stem portion extendsabove said uppermost first face and is resiliently disposed directlyagainst said upper portion of said insulating body where said flexiblestem portion extends out of said recess.
 8. The connector as in claim 1,wherein said insulating body comprises a row of said adjacently disposedrecesses defined in each of said sides with a respective said connectorelement disposed in each said recess.
 9. The connector as in claim 8,wherein said insulating body is generally symmetrical about a planeextending between said rows of adjacently disposed recesses.
 10. Theconnector as in claim 1, wherein said contact foot of each saidconnector comprises a contacting surface facing in an opposite directionfrom said contact head.
 11. The connector as in claim 10, wherein saidbottommost face of said insulating body is configured for dispositionadjacent a face of the second circuit board, said contact foot of eachsaid connector extending sufficiently beyond a plane of said bottommostface so that said contact feet make electrical connection with matingpads of the second circuit board upon said bottommost face beingdisposed directly adjacent the face of the second circuit board, saidconnector thereby disposed between the first and second circuit boards.12. The connector as in claim 1, wherein said contact foot of each saidconnector comprises a contacting surface facing in the same direction assaid contact head.
 13. The connector as in claim 12, wherein saidcontact foot of each said connector extends outward from said insulatingbody between planes through said uppermost and bottommost faces so thatsaid contact feet make electrical connection with mating pads of thesecond circuit board.